Sunday, January 8, 2006

Saturn

This photo looks like something right out of one of the pulp science fiction novels I devoured as a kid:

From the official Cassini website:

In this magnificent view, delicate haze layers high in the atmosphere encircle the oblate figure of Saturn. A special combination of spectral filters used for this image makes the high haze become visible. A methane-sensitive filter (centered at 889 nanometers) makes high altitude features stand out, while a polarizing filter makes small haze particles appear bright.

Methane in the atmosphere absorbs light with wavelengths around 889 nanometers as it travels deeper into the gas planet, thus bright areas in this image must represent reflective material at higher altitudes. Small particles or individual molecules scatter light quite effectively to a polarization of 90 degrees, which this polarizing filter is sensitive to. Thus, high altitude haze layers appear bright in this view.

The small blob of light at far right is Dione (1,126 kilometers, or 700 miles across).

The image was taken with the Cassini spacecraft wide-angle camera on Dec. 5, 2005, at a distance of approximately 2.9 million kilometers (1.8 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 100 degrees. The image scale is 169 kilometers (105 miles) per pixel.

Think about that last little bit. If you click on the small picture above right to get the larger view, each dot on that photo is an area 105 miles square on Saturn. That’s a big place! Saturn’s surface area is about 84 times that of our Earth’s. Much more information on Saturn at Wikipedia